1. Field of the Invention
The present invention relates to an adjustable barbell or dumbbell or exercise device, and more particularly to an adjustable barbell or dumbbell or exercise device including an improved structure for allowing the weight members to be easily and adjustably attached to or disengaged from the weight carrier or handle and for allowing the adjustable dumbbell to be easily operated by the users.
2. Description of the Prior Art
Typical barbells or dumbbells comprise a handle to be grasped or held by the user, and a number of weight plates to be attached onto the ends of the handle for weight lifting or exercising purposes, or for exercising or training the upper muscle groups or the lower muscle groups of the user.
For example, U.S. Pat. No. 4,566,690 to Schook, U.S. Pat. No. 5,135,455 to King et al., U.S. Pat. No. 5,180,352 to Sreter, and U.S. Pat. No. 5,242,350 to Chang disclose several typical adjustable dumbbells each comprising two or more weight plates or weight members selectively or adjustably attaching or mounting onto the handle shaft or handle bar for being held or grasped by the users to train the upper muscle groups or the lower muscle groups of the user.
However, the weight plates or weight members are normally attached or mounted onto the handle shaft or handle bar with a threading engagement such that it takes a long time to thread and unthread the weight plates or weight members onto or from the handle shaft or handle bar.
U.S. Pat. No. 5,250,014 to Chang discloses another typical adjustable dumbbell comprising two spherical shells joined by a short bar with lock screw bolts for receiving or attaching counter weights within the spherical shells.
However, it also takes a long time to thread and unthread the lock screw bolts relative to the spherical shells in order to attach or mount the weight plates or weight members onto or from the spherical shells.
U.S. Pat. No. 6,656,093 to Chen discloses a further typical dumbbell comprising a handle which can be grasped or held by the user, a number of weight plates to be attached onto the ends of the handle for exercising or training the arms or the feet of the user, and a latch attached onto the end of the handle and/or the weighted plates for selectively or adjustably mounting or securing the weighted plates on the ends of the handle.
However, the latch may not be easily or quickly assembled onto the handle or the weighted plates such that the typical adjustable dumbbell may not be easily or quickly assembled or manufactured.
U.S. Pat. No. 7,731,641 to Chen discloses a still further typical adjustable dumbbell comprising a series of weighted plates to be attached onto the ends of the handle, and a lock nut should be attached onto the ends of the handle for selectively or adjustably mounting or securing or anchoring the weighted plates on the ends of the handle.
However, it also takes a long time to thread and unthread the lock nuts relative to the handle in order to attach or mount the weight plates or weight members onto or from the ends of the handle.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional adjustable dumbbells.